The present invention relates primarily to flashlights, and in particular to a flashlight which can conveniently be held, turned "OFF" and "OFF" and the focal length of the light beam selectively changed by one hand operation.
Various flashlight designs have addressed improvements to the optical characteristics of the flashlight. For example, certain designs incorporate variable light beam focal lengths. Some of these prior art devices are taught by U.S. Pat. Nos. 4,577,263; 4,658,336; 4,841,417; and 4,899,265.
In general these prior art devices facilitate beam focal length change by relative rotation of various portions of the flashlight housing.
One of the disadvantages of certain flashlights regardless of size is that these designs, although successful in enabling the light beam to be turned "ON" and "OFF" and the light beam focal length to be changed, is that these designs are such as to make the switching "ON" and "OFF" and the focusing of the light beam awkward, if not impossible to accomplish with the hand that is holding the flashlight by its barrel, or, handle. Because there exists a wide variety of uses for hand-held flashlights wherein the use would be facilitated by having a design such that the flashlight could be held in one hand, the light beam switched "ON" and "OFF" and focused with ease by the same one hand, it may be seen as a deficiency in this art that heretofore no flashlight combining features that provide such ease of operation has been previously developed. It is therefore desirable to provide a flashlight held in one hand and for which switching and focusing operations may be performed with the hand holding the flashlight with ease without requiring the holding hand to change its grip on the flashlight while switching and focusing. It is also desirable in certain circumstances to provide a flashlight having "one hand" operation where a particular focal length is maintained until further adjustment and switching and adjusting of the light beam focal length can be performed remote from the location of the flashlight.
The instant invention advances the hand held flashlight art in the areas of these certain deficiencies in the prior art flashlights.